Message=Index was out of range. Must be non-negative and le

edit the selected row in gridview and focus remain on selection

error :  Message=Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index


private void btnEdit_Click(object sender, EventArgs e)
        {
            int id = Convert.ToInt32(grdShow.SelectedRows[0].Cells[0].Value.ToString());
            object[,] ObjEditProductDetails = new object[,] { {"@ProductId",id},{ "@ProductName", txtProductName.Text }, { "@Manufacturer", txtManufactorer.Text }, { "Rate",txtRate.Text } };
            DB.ExecuteNonQuery_SP("Sp_UpdateProductDetails",ObjEditProductDetails);
            int RowIndex = 0;
            if (grdShow.Rows.Count > 0)
            {
                RowIndex = grdShow.SelectedRows[0].Index;
               
            }

            ShowGridView();
            grdShow.SelectedRows[RowIndex].Selected = true;
           
           
            ClearControls();
        }